Special Counsel Jack Smith appears to have a powerful partner in his case against President Trump for unlawfully keeping documents at Mar-a-Lago — the National Archives and Records Administration, the very agency tasked with chaperoning the president’s secrets.

The link between Mr. Smith’s criminal investigation and the National Archives surfaces a surprising sight: Two organs of the executive branch — the archives and the Department of Justice, under whose auspices Mr. Smith works — joining forces to effectuate the indictment of a former president, in whom all the executive branch’s authority once was vested. 

The role of the National Archives in helping Mr. Smith comes even as congressional testimony on Wednesday from the organ’s chief operating officer, William Bosanko,  disclosed that from every “administration from Reagan forward, we have found classified information in unclassified boxes.” 

Mr. Trump is not the only high official who has come under scrutiny. A special counsel was appointed to scrutinize President Biden’s storage after documents were found at a range of unauthorized locations. Vice President Pence’s retention arrangement has also come in for questioning.   

The National Archives — complying with subpoenas issued by the special counsel — is reportedly set to turn over to Mr. Smith a batch of 16 records that show that Mr. Trump’s team knew of the proper declassification process well before the FBI arrived at his Mar-a-Lago manse, search warrant in hand.    

According to CNN, the acting archivist, Debra Steidel Wall, sent a letter to Mr. Trump on Tuesday telling him that the “16 records in question all reflect communications involving close presidential advisers, some of them directed to you personally, concerning whether, why, and how you should declassify certain classified records.”

Ms. Wall tells Mr. Trump that Mr. Smith “is prepared to demonstrate with specificity to a court, why it is likely that the 16 records contain evidence that would be important to the grand jury’s investigation.” She warns that the 16 documents will be handed over on May 24 unless a court intervenes. Mr. Smith has, she notes, requested more than 100 boxes of material.   

News of the records comes days after Mr. Trump told CNN’s Kaitlan Collins that he had “every right” to take the documents from the White House and that he “didn’t make a secret of it. You know, the boxes were stationed outside the White House, people were taking pictures of it.”

Mr. Trump added that the records “become automatically declassified when I took them.” The documents provided to the special counsel, though, could undercut that defense by indicating that Mr. Trump possessed the requisite intent to run afoul of the Espionage Act, obstruction of justice, or other related statutes. 

One of Mr. Trump’s lawyers, James “Jim” Trusty, is test driving a defense on television, explaining, “At the end of his presidency, he relied on the constitutional authority as commander-in-chief, which is to take documents and take them to Mar-a-Lago while still president as he was at the time, and to effectively declassify and personalize them.”

In this vein, Mr. Trump argued last year, “You can declassify just by saying, ‘It’s declassified,’ even by thinking about it.” Ms. Wall indicates that Mr. Trump has asserted “constitutionally based privilege” to block some of the materials from passing from the National Archives into Mr. Smith’s hands and, potentially, morphing into predicates for an indictment.     

Should the documents case go to court, the Presidential Records Act, signed into law by President Carter in 1978, will likely be at the center of the litigation over Mr. Trump’s culpability. As the Congressional Research Service explains, that statute ordained that “presidential records are the property of the United States” rather than the president’s private property.

The CRS notes: “In the event of potentially unlawful removal or destruction of government records” the act “requires the head of a federal agency to notify the Archivist, who initiates action with the Attorney General for the possible recovery of such records.” It is not clear — yet — when unlawful removal becomes criminal.